1. Field
A linear compressor is disclosed herein.
2. Background
In general, compressors may be mechanisms that receive power from power generation devices, such as electric motors or turbines, to compress air, refrigerants, or other working gases, thereby increasing a pressure of the working gas. Compressors are widely used in home appliances or industrial machineries, such as refrigerators and air-conditioners.
Compressors may be largely classified into reciprocating compressors, in which a compression space, into which and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a piston and a cylinder to compress the refrigerant while the piston is linearly reciprocated within the cylinder; rotary compressors, in which a compression space, into and from which a working gas, such as a refrigerant is suctioned and discharged, is defined between a roller, which is eccentrically rotated, and a cylinder to compress the refrigerant while the roller is eccentrically rotated along an inner wall of the cylinder; and scroll compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between an orbiting scroll and a fixed scroll to compress the refrigerant while the orbiting scroll is rotated along the fixed scroll. In recent years, among the reciprocating compressors, linear compressors having a simple structure in which a piston is directly connected to a drive motor, which is linearly reciprocated, to improve compression efficiency without mechanical loss due to switching in moving, are being actively developed. Generally, such a linear compressor is configured to suction and compress a refrigerant while a piston is linearly reciprocated within a cylinder by a linear motor in a sealed shell, thereby discharging the compressed refrigerant.
The linear motor has a structure in which a permanent magnet is disposed between an inner stator and an outer stator. The permanent magnet may be linearly reciprocated by a mutual electromagnetic force between the permanent magnet and the inner (or outer) stator. Also, as the permanent magnet is operated in a state in which the permanent magnet is connected to the piston, the refrigerant may be suctioned and compressed while the piston is linearly reciprocated within the cylinder and then be discharged.
A linear compressor according to the related art is disclosed in Korean Patent Publication No. 10-2010-0010421. The linear compressor according to the related art may include an outer stator, an inner stator, and a permanent magnet, which form a linear motor. The permanent magnet may be connected to an end of a piston. When the permanent magnet linearly reciprocates due to a mutual electromagnetic force between the inner stator and the outer stator, the piston linearly reciprocates in a cylinder along with the permanent magnet.
According to the related art, while the piston repeatedly moves within the cylinder, interference between the cylinder and the piston may occur causing abrasion of the cylinder or piston. More particularly when a predetermined pressure (a coupling pressure) acts on the piston causing deformation of the piston due to pressure, interference between the cylinder and the piston may occur. Also, if a slight error occurs while the piston is assembled with the cylinder, a compression gas may leak to the outside, and thus, abrasion between the cylinder and the piston may occur.
As described above, interference between the cylinder and the piston may occur causing interference between the permanent magnet and the inner and outer stators, thereby damaging components. Also in a case of the related art linear compressor, each of the cylinder or the piston may be formed of a magnetic material. Thus, a large amount of flux generated in the linear motor may leak to the outside through the cylinder and piston, deteriorating efficiency in the compressor.